But if things had gone according to plan for Cruise, he would have celebrated hitting the half-century mark in Iceland -- with Katie Holmes by his side. An insider tells the new issue of Us Weekly, out now, that Cruise had been planning his own "surprise" birthday bash to be held Tuesday. While Holmes, 33, had been noticeably absent from Rock of Ages premieres and a recent Friars Club roast, "he begged her to come to Iceland for one last try at reconciliation," the insider says.

Holmes -- secretly plotting to file for divorce and move into her own rented NYC apartment -- refused, and the pair had a "huge fight," the source explains.

Although Cruise was aware that things were tense and severely estranged with Holmes, "he was confident he could talk her out of it and keep her with him," the source says. Holmes filed for divorce last Thursday, and seeks sole legal custody of daughter Suri, 6.